Hi Guys, im trying to print a new gear knob for the car.
its a fairly standard m10x1.5 (course) thread but really struggling to get it to print the thread.
I used this as a guide
https://www.onshape.com/videos/lets-make-a-nut
but the printer still struggles.
whilst the external dimensions match my cad file im finding im having to trial and error the internal dimensions a long way off what they should be.
any suggestions? Or am i just asking too much of my friend’s printer?
This is zero help for the question as asked, but I’ve never gotten internal threads to print reliably. I make a recess big enough for a metal insert, thread the insert, heat it up, and press it into the 3d print.
@John_Bump yeh I’m contemplating a nut
In theory it should work, but in practice it’ll be real rough going. You’d probably be better off tapping the nut to the desired size and pitch.
The threads on a 1.5mm pitch screw are 0.921mm deep. With a .4mm nozzle that’s technically possible, you’re not trying to print smaller structures than the nozzle size, but it’s so small and requires such accuracy for smooth threading you’re probably not going to get it working the way you like.
The most success I’ve had with printing internal threads on filament based printers is with very deep threads and ideally a larger more rounded profile on the thread.
Your typical V-shaped thread will be tough, even at higher pitches with deeper threads.
The other alternative is to use a resin printer, that will produce the threads you want beautifully. Unfortunately the resin it prints in can be a bit brittle, so it’s not really suitable for production mechanical use.
I’d recommend printing a hole and cutting your own threads with a tap. Or print a hole just a little smaller than the bolt, and screw it right on, the bolt will tap itself into the hole (this works with 3-5 mm bolts, I’ve never tried with bigger).
Has it been done? Yes. Should you? Not really. If you don’t mind having it be two pieces, entrap the nut. I am one of few who drive a stick shift in the US, so unless I want to order one, it’s easier to print. You don’t want to shift and then learn your plastic threads stripped out and the knob comes off.
You need a really good part cooling fan duct and use layers 0.05mm thick. Use a 0.4mm nozzle to get good overlap on sloped edges.
As another alternative measure the outer diameter of the threads and make the hole 0.3mm smaller on your part file. When it prints it will print 0.8mm smaller than measured (tolerance if you are not under or over extruding) and allow you to let it self thread. As the threads cut it will push material out of the way into the threads on the post. Might be enough to hold it in place for you without trying to actually print the threads themselves.
Huh, M10 should be pretty easy. I print M6 female threads without too much trouble. Just use really low layer height (like .1) so the 60 degree overhangs work out, and make sure your printer has zero backlash + good extrusion volume calibration.
Put the nut into the print as it prints. Pause it if you have to, but it’s more fun getting the timing right.